Color Band Resistors Essay Example for Free

Color Band Resistors EssayRESISTORA resistor is a instalment of a circuit that resists the flow of electrical current. It has two entrepots across which electricity must pass, and it is designed to drop the potency of the current as it flows from one terminal to the other. Resistors are primarily used to create and maintain known safe currents within electrical components.Resistors are coated with paint or enamel, or cover in molded plastic to protect them. Because they are often too small to be written on, a standardized color-coding system is used to order them. The first three colors represent ohm value, and a fourth indicates the adjustment, or how close by percentage the resistor is to its ohm value. This is important for two reasons the nature of its grammatical construction is imprecise, and if used above its maximum current, the value can change or the unit itself can burn up. RESISTANCEIn physics, electric resistance is defined as the ability of a substance to pr event or resist the flow of electrical current. A substance resists electrical current because of a collision amidst electrons and atoms, which slows the electrons down and converts nearly of their energy to heat energy. In some cases, the energy is also converted into light.German physicist Georg Ohm (1789-1854) is credited with discovering the effect of a materials make up, space and thickness on its resistance. In fact, the standard unit of measuring resistance, the ohm, is named after him. Ohms law became publicly known in 1827 and states that a circuits resistance is 1 ohm if a 1-volt voltage make 1 amp of current. According to Ohms law, a circuits resistance is equal to its voltage divided by the amount of current. electrical resistanceThe measure of the potential electrical resistance of a conductive material. It is determined experimentally using the equation pic = RA/l, where R is the measured resistance of some length of the material, A is its cross-sectional area (whic h must be uniform), and l is its length. It is measured in ohm-meters.Resistivity of a material remains constant whether it is taken about 1 cm..or 1km (on a constant temperature and other physical conditions remains the same)The Resistivity of a material dep turn backs on temperature( and other physical conditions such as air pressure) and the nature of the material (avaibility of free electrons.number of free electrons are same in an element atoms). TEMPERATURE COEFFICIENTThe temperature coefficient is the relative change of a physical property when the temperature is changed by 1 Kelvin.In the following formula, let R be the physical property to be measured and T be the temperature at which the property is measured. T0 is the citation temperature, and T is the difference between T and T0. Finally, is the (linear) temperature coefficient. Given these definitions, the physical property ispicHere has the dimensions of an inverse temperature (1/K or K1).This equation is linear wi th reward to temperature. For quantities that motley polynomially or logarithmically with temperature, it may be possible to calculate a temperature coefficient that is a useful approximation for a certain range of temperatures. For quantities that vary exponentially with temperature, such as the rate of a chemical reaction, any temperature coefficient would be valid only over a very small temperature range. distinct temperature coefficients are specified for various applications, including nuclear, electrical and magnetic.1. What are the uses of resistors? Resistors are essential in electronic circuits, as they control the amount of current that runs through them. Without resistors voltage would be too great for individual components to handle and would result in overloading or destruction.The principle by which resistors work can also be utilize to heating elements in irons, toasters, heaters, electric stoves and hair dryers, which dissipate voltage as heat. Variable resistors may function as sensors, switches or voltage dividers. Specialist end uses, such as new generation automotive LED light clusters, demand a specialist resistor solution. Aluminum clad wire infract resistors provide high power dissipation in a limited space, and are designed for direct heat sink mounting, using thermal meld to achieve maximum performance. The resistors work as a ballast to augment the resistance in the LED, mimicking that of a conventional2. What is the difference between 4 color, 5 color, and 6 color band resistors? 4 Color Band Resistors- These resistors have two bands for the resistance value and 1 band for the multiplier and 1 tolerance band. This is the most common variation. 5 Color Band Resistors- These are with high precision and have an extra band to indicate a 3rd world-shattering digit. The first three bands indicate the significant digits, the 4th band is the multiply factor and the 5th represents the tolerance. There are exceptions to this. For exampl e, sometimes the extra band indicates nonstarter rate or temperature coefficient. 6 Color Band Resistors- These are resistors that are usually for high precision that have an additional band to specify the temperature coefficient (ppm/k). The 1st three bands are for the resistance value, the 4th for the multiplier, the 5th for the tolerance and the 6th for the temperature coefficient.Sourceshttp//www.wisegeek.com/what-is-a-resistor.htmhttp//www.wisegeek.com/in-physics-what-is-resistance.htmhttp//in.answers.yahoo.com/question/index?qid=20100627073410AAvDj3T http//www.thefreedictionary.com/resistivity http//en.wikipedia.org/wiki/Temperature_coefficienthttp//www.rapidonline.com/infozone/resistors/applications.htm